<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title></title>
    <script src="https://cdn.jsdelivr.net/npm/vue"></script>
    <style>
        .active {
            width: 100px;
            height: 100px;
            background-color: tan;
        }
        
        .current {
            color: red;
        }
        
        .myFont {
            font-size: 20px;
            font-weight: 800;
        }
    </style>
</head>

<body>
    <div id="app">
        <p :class="{active:bool1,current:bool2}">111</p>
        <p :class="{active:num==10}">222</p>
        <hr>

        <p :class="['active','current']">333</p>
        <p :class="classArr">444</p>
        <hr>

        <p :class="num>15?'active':'current'">555</p>
        <hr>
    </div>

    <script>
        new Vue({
            el: '#app',
            data: {
                bool1: true,
                bool2: true,
                bool3: false,
                classArr: ['active', 'current'],
                num: 10
            }
        })
    </script>
</body>

</html>